diff --git a/src/s_sincosl.c b/src/s_sincosl.c
index c587a1b..e2d3a34 100644
--- a/src/s_sincosl.c
+++ b/src/s_sincosl.c
@@ -26,6 +26,6 @@
 OLM_DLLEXPORT void
 sincosl( long double x, long double * s, long double * c )
 {
-    *s = cosl( x );
-    *c = sinl( x );
+    *s = sinl( x );
+    *c = cosl( x );
 }